That's dodging the point. If you forget whether your list A is an association list ((key value)) or a reverse association list ((value key)), your cars and cdrs won't crash the program, but your program will still fail to produce a correct result, and the source of the bug is a type error.
I'm fully aware of the errors that can arise from dynamic typing in Common Lisp. It's just not my experience that it's that big of a deal.
The reverse association list is contrived compared to the issues one can have in Python or Ruby. Most people just use association lists the normal way and use rassoc as needed.
Lets not kid ourselves and pretend that a reversed assoc list is used in place of a normal rassoc or find :key #'cdr.
Comments
That's dodging the point. If you forget whether your list A is an association list ((key value)) or a reverse association list ((value key)), your cars and cdrs won't crash the program, but your program will still fail to produce a correct result, and the source of the bug is a type error.
The universe of common errors you can have in Common Lisp due to dynamic typing is constrained compared to Python and Ruby.
I say this as someone who works with Python daily as my working language and grew up with a copy of this:
http://www.cs.cmu.edu/afs/cs/Web/Groups/AI/lang/lisp/impl/cl...
I'm fully aware of the errors that can arise from dynamic typing in Common Lisp. It's just not my experience that it's that big of a deal.
The reverse association list is contrived compared to the issues one can have in Python or Ruby. Most people just use association lists the normal way and use rassoc as needed.
Lets not kid ourselves and pretend that a reversed assoc list is used in place of a normal rassoc or find :key #'cdr.